INSTALLATION

10.Perform a final check of the completed system wiring to ensure that all connections are accurate. Check all power and ground connections for frayed wires and loose connections which could cause problems.

NOTE: Follow the diagrams for proper signal polarity.

!CAUTION: These amplifiers are not recommended for impedance loads below 2.

USING PASSIVE CROSSOVERS

A passive crossover is a circuit that uses capacitors and/or coils and is placed on speaker leads between the amplifier and speaker. The crossover delegates a specific range of frequencies to the speaker for optimum driver performance. A crossover network can perform one of three functions: High-Pass (capacitors), Low- Pass (inductors or coils) and Bandpass (combination of capacitor and coil).

The most commonly used passive crossover networks are 6dB/octave systems. These are easy to construct and require one component per filter. Placing this filter in series with the circuit will reduce power to the speaker by 6dB/octave above or below the crossover point depending on whether it is a high-pass or low-pass filter. More complex systems such as 12dB/octave or 18dB/octave can cause impedance problems if not professionally designed.

Passive crossovers are directly dependent upon the speaker's impedance and component value for accuracy. When passive crossover components are used in multiple speaker systems, the crossover's effect on the overall impedance should be taken into consideration along with the speaker's impedance when determining amplifier loads.

CAUTION: These amplifiers

!are not recommended for impedance loads below 2.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6dB/Octave Low-Pass

 

6dB/Octave High-Pass

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Freq.

 

 

 

Speaker Impedance

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hertz

2 OHMS

 

4 OHMS

 

 

 

 

8 OHMS

 

L

 

C

 

 

L

 

 

C

 

 

 

L

 

C

 

80

4.1mH

1000µF

 

8.2mH

500µF

 

 

16mH

250µF

100

3.1mH

 

800µF

 

6.2mH

400µF

 

 

12mH

200µF

130

2.4mH

 

600µF

 

4.7mH

300µF

 

 

10mH

150µF

200

1.6mH

 

400µF

 

3.3mH

200µF

 

 

6.8mH

100µF

260

1.2mH

 

300µF

 

2.4mH

150µF

 

 

4.7mH

 

75µF

400

.8mH

 

200µF

 

1.6mH

100µF

 

 

3.3mH

 

50µF

600

.5mH

 

136µF

 

1.0mH

 

 

68µF

 

 

2.0mH

 

33µF

800

.41mH

 

100µF

 

.82mH

 

 

50µF

 

 

1.6mH

 

26µF

1000

.31mH

 

78µF

 

.62mH

 

 

39µF

 

 

1.2mH

 

20µF

1200

.25mH

 

66µF

 

.51mH

 

 

33µF

 

 

1.0mH

 

16µF

1800

.16mH

 

44µF

 

.33mH

 

 

22µF

 

 

.68mH

 

10µF

4000

.08mH

 

20µF

 

.16mH

 

 

10µF

 

 

.33mH

 

5µF

6000

51mH

 

14µF

 

.10mH

 

6.8µF

 

 

.20mH

 

3.3µF

9000

34mH

 

9.5µF

 

68mH

 

4.7µF

 

 

.15mH

 

2.2µF

12000

25mH

 

6.6µF

 

51mH

 

3.3µF

 

100mH

 

1.6µF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L = Low-Pass (Inductor)

C = High-Pass (Capacitor)

For more information, see your Authorized Rockford

Fosgate Dealer.

7

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Image 7
Rockford Fosgate 351M manual Speaker Impedance, Using Passive Crossovers

351M specifications

Rockford Fosgate is a brand synonymous with premium sound performance, particularly in the realm of car audio equipment. One of their standout products is the Rockford Fosgate 351M, a powerful marine amplifier designed to deliver exceptional audio clarity and loudness in rugged environments, such as on boats and other watercraft.

The Rockford Fosgate 351M is a 3-channel amplifier that brings versatility and power to any marine audio setup. With an impressive power output of 50 watts per channel at 4 ohms, it ensures that audio enthusiasts can enjoy their music with remarkable depth and clarity, even in the noisy environment of an open water setting. This amplifier is also capable of delivering a maximum output power of up to 150 watts at 2 ohms, making it ideal for driving multiple speakers with ease.

One of the remarkable features of the 351M is its Class D topology, which promotes greater efficiency and reduces heat production compared to traditional amplifier designs. This ensures that the amplifier performs optimally without the risk of overheating, even during extended listening sessions. Additionally, its compact size allows for easy installation in limited spaces, making it a practical choice for any marine audio system.

The 351M is built with marine-grade materials, offering IPX6 water and dust protection. This means it can withstand splashes and saltwater exposure, providing peace of mind for users who wish to use it in challenging outdoor conditions. The amplifier's rugged construction ensures a long lifespan and reliable performance, even in the harshest marine environments.

Integrated features such as integrated crossover filters allow users to tailor their sound more precisely. This ensures that highs, mids, and lows can be optimized for various speaker systems, providing a truly immersive listening experience. Furthermore, the amplifier comes with RCA line outputs, enabling easy expansion and linking with additional amplifiers if required.

The Rockford Fosgate 351M is the ideal solution for marine audio enthusiasts seeking quality amplification for their sound systems. With its advanced technology, durable construction, and user-friendly features, it stands out as a top choice for those looking to enhance their boating experience with high-performance audio. Whether you're cruising on a lake or taking on the open sea, the 351M provides the power and clarity needed to enjoy your favorite tunes.